论文标题
关于（缺乏）大型星系恒星质量功能的（缺乏）从$ z $ = 1.5到0.4
On the (Lack of) Evolution of the Stellar Mass Function of Massive Galaxies from $z$=1.5 to 0.4
论文作者
论文摘要
我们研究了超过$ 0.4 <z <1.5 $的最高质量星系的数量密度的演变（覆盖9 Gyr）。我们使用Spitzer/Hetdex探索性大区域（Shela）调查，该调查涵盖17.5 $ \ MATHRM {deg}^2 $，其中八个光度频段横跨SDSS Stripe 82字段中的0.3-4.5 $μm。这种尺寸会产生最低的计数不确定性和宇宙差异，但对于$ z \ sim1.0 $，大规模星系却产生了大规模星系。我们使用$ \ log（m_ \ ast/m_ \ odot）> 10.3 $使用前向模型方法研究星系的出色质量函数（SMF），该方法充分说明了恒星质量上的统计和系统不确定性。从$ z $ = 0.4到1.5，SMF的巨大末端显示出其形状最小的演变：特征性质量（$ m^\ ast $）的进化不到0.1 dex（$ \ pm $ 0.05 dex）;带有$ \ log（m_ \ ast/m_ \ odot）的星系的数字密度密度> 11 $在$ \ log（n/\ mathrm {mpc}^{ - 3} { - 3}）$ $ \ simeq $ $ - $ 3.4（$ \ pm $ 0.05），$ \ log \ log \ log \ log \ log （n/\ mathrm {mpc}^{ - 3}）$ = $ - $ 3.7（$ \ pm $ 0.05）$ z $ = 1.5。我们讨论了SMF中的不确定性，这些不确定性是由星形形成历史中的假设和恒星种群合成模型的细节主导的。对于静态星系，数据与特征性质量或数字密度（$ z \ sim 1.5 $ for现在）的质量密度或数字密度为单位（$ \ lyssim0.1 $ dex）是一致的。这意味着，静止的大型星系人群的任何质量增长（大概是通过“干”合并）都必须平衡后期恒星进化的质量损失率，以及从星形形成人群中形成淬火星系。我们提供了这种质量增长的限制，从$ z = 1.0 $到$δm_\ ast/m_ \ ast \ aSt \ leq $ 45％（即$ 10^{11} $ $ $ m_ \ odot $的$ 10^{11}} $ 10^{11}} $ 10^{11} $ 10^{11} $ $ odot $。
We study the evolution in the number density of the highest mass galaxies over $0.4<z<1.5$ (covering 9 Gyr). We use the Spitzer/HETDEX Exploratory Large-Area (SHELA) Survey, which covers 17.5 $\mathrm{deg}^2$ with eight photometric bands spanning 0.3-4.5 $μ$m within the SDSS Stripe 82 field. This size produces the lowest counting uncertainties and cosmic variance yet for massive galaxies at $z\sim1.0$. We study the stellar mass function (SMF) for galaxies with $\log(M_\ast/M_\odot)>10.3$ using a forward-modeling method that fully accounts for statistical and systematic uncertainties on stellar mass. From $z$=0.4 to 1.5 the massive end of the SMF shows minimal evolution in its shape: the characteristic mass ($M^\ast$) evolves by less than 0.1 dex ($\pm$0.05 dex); the number density of galaxies with $\log (M_\ast/M_\odot) >11$ stays roughly constant at $\log (n/\mathrm{Mpc}^{-3})$ $\simeq$ $-$3.4 ($\pm$0.05), then declines to $\log (n/\mathrm{Mpc}^{-3})$=$-$3.7 ($\pm$0.05) at $z$=1.5. We discuss the uncertainties in the SMF, which are dominated by assumptions in the star formation history and details of stellar population synthesis models for stellar mass estimations. For quiescent galaxies, the data are consistent with no (or slight) evolution ($\lesssim0.1$ dex) in the characteristic mass nor number density from $z\sim 1.5$ to the present. This implies that any mass growth (presumably through "dry" mergers) of the quiescent massive galaxy population must balance the rate of mass losses from late-stage stellar evolution and the formation of quenching galaxies from the star-forming population. We provide a limit on this mass growth from $z=1.0$ to 0.4 of $ΔM_\ast/M_\ast\leq$ 45% (i.e., $\simeq0.16$ dex) for quiescent galaxies more massive than $10^{11}$ $M_\odot$.
